Method for removing heat degradable textile waste material from apparatus used in textile operations

ABSTRACT

In a method for removing tenaciously adhered heat degradable textile waste material from apparatus used in textile operations, a flowing stream of air is delivered through an electrical resistance heater to be heated to an elevated temperature and is then directed against the waste material to be removed. Electrical energization of the heater is coordinated with the delivery of the flowing stream of air in such a manner as to protect the heater against premature failure otherwise possibly occurring due to energization thereof while no air is flowing therethrough.

United States Patent Henderlite, III

METHOD FOR REMOVING HEAT DEGRADABLE TEXTILE WASTE MATERIAL FROM APPARATUS USED IN TEXTILE OPERATIONS Inventor:

James 11. l-lenderlite, 111, Charlotte,

Assignee:

Filed:

Air Knife, 1nc., Charlotte, NC.

Aug. 20, 1973 Appl. No.: 389,899

Related US. Application Data US. Cl

Int. Cl

Division of Ser. No. 233,107, March 9, 1972.

134/37, 134/5, 134/19 B08b 5/02 Field of Search 219/369, 370, 373, 374,

References Cited UNITED STATES PATENTS Schluter 219/381 Potter 2I9/370 X Richardson et al 219/373 UX Kaminsky 219/374 X [451 Oct. 15, 1974 3,270,182 8/1966 Hynes 219/382 3,305,184 2/1967 Sercss ct al..... 134/37 3,371,188 2/1968 Henes et a1. 219/373 3,429,745 2/1969 Black, Jr 134/37 3,523,827 8/1970 Sims 134/37 FOREIGN PATENTS OR APPLICATIONS 752,165 9/1933 France 219/379 Primary ExaminerS. Leon Bashore Assistant Examiner-Richard V. Fisher Attorney, Agent, or FirmParrott, Bell, Seltzer, Park & Gibson ABSTRACT In a method for removing tenaciously adhered heat degradable textile waste material from apparatus used in textile operations, a flowing stream of air is delivered through an electrical resistance heater to be heated to an elevated temperature and is then directed against the waste material to be removed. Electrical energization of the heater is coordinated with the delivery of the flowing stream of air in such a manner as to protect the heater against premature failure otherwise possibly occurring due to energization thereof while no air is flowing therethrough.

3 Claims, 12 Drawing Figures smmll PNENIED 081 I 5 I974 SHEET 10F 3 PAIENTEUum 1 5mm SHEET 3 BF 3' METHOD FOR REMOVING HEAT DEGRADABLE TEXTILE WASTE MATERIAL FROM APPARATUS USED IN TEXTILE OPERATIONS This application is a division of copending Application Ser. No. 233,107, filed Mar. 9, 1972, and entitled APPARATUS AND METHOD FOR REMOVING TEXTILE WASTE MATERIAL.

A recurrent problem encountered in textile mills is the removal of textile waste material from apparatus used in the textile operations. As is known to operators working in textile mills, particular problems are presented where textile waste material becomes entangled or wrapped about an axle or shaft so as to impede proper rotation of a rotating element. One example of such a problem is the entanglement of waste material about the axle of a caster such as are used on carts and the like in textile mills.

I-Ieretofore, the removal of such textile waste material has conventionally been accomplished through the use of a knife or other sharp-edge instrument. At least two difficulties are introduced by such an attempt at removal, namely difficulty in gaining access to the textile waste material wrapped about a caster axle or the like and damage to the apparatus from which the textile waste material is being removed. The latter difficulty is particularly important with removal of textile waste material from bobbins, spools or the like.

The present invention overcomes the difficulties and deficiencies of prior methods and apparatus from removing heat degradable textile waste material by use of a flowing stream of heated air which may readily penetrate into confined spaces and remove the waste material therefrom and which does not damage the appara tus from which the tenaciously adhered heat degradable textile waste material is being removed.

It is an object of this invention to protect an electrical resistance heater used to heat a flowing stream of air to an elevated temperature against premature failure otherwise possibly occurring by coordinating the electrical energization of the heater with the delivery of a flowing stream of air therethrough to be directed against waste material to be removed. In realizing this object of the present invention, operative interconnection with both the means by which the flowing stream of air is delivered and the electrical resistance heater is established and energization of the electrical heater in the absence of delivery of air is substantially precluded.

A further object of this invention is to provide, a method of removing tenaciously adhered heat degradable textile waste material, for the self-limiting of the temperatures attained by an electrical resistance heater. In accomplishing this object of the present invention, a flowing stream of air at a predetermined volume rate of flow is delivered to and through an electrical resistance heater having a positive temperature coefficient resistance element. Due to the variance in the resistance of the heater with temperature, the wattage of power consumed by the heater and thus the temperature attained by the heater have a tendency towards self-limitation. As the temperature of the heater rises and the wattage of power consumed is reduced, an equilibrium is reached which, with flow rates as provided by this invention, precludes destructive heating of the resistance element.

Some of the objects and advantagesof the invention having been stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which FIG. 1 is a perspective view of a first embodiment of apparatus in accordance with this invention;

FIG. 2 is an elevation view of the apparatus of FIG. 1 with a coverplate removed to reveal components of the apparatus mounted within a housing;

FIG. 3 is an elevation view, partially in section, taken generally as indicated by the line 3-3 in FIG. 2;

FIG. 4 is a plan view, partially in section, through a portion of the apparatus of FIG.,1 taken generally as indicated by the line 44 in FIG. 1;

FIG. 5 is an enlarged elevation view, in section, through a portion of the apparatus shown in FIG. 4, taken generally as indicated by the line 5-5 in that figure;

FIG. 6 is a section view taken by'the line 6-6 in FIG. 5;

FIG. 7 is an enlarged elevation view, in section, taken generally as indicated by the line 7 7 in FIG. 4;

FIG. 8 is a sectional view taken as indicated by the line 8-8 in FIG. 7;

FIG. 9 is a schematic drawing of the apparatus of FIG. 1;

FIG. 10 is a view similar to FIG. 1, showing a second embodiment of the apparatus of this invention;

FIG. 11 is a detail view showing a pressure responsive electrical switch means incorporated in the apparatus of FIG. 10; and

FIG. 12 is a schematicdiagram similar to FIG. 9 and showing the apparatus of FIG. 10.

While first and second embodiments of apparatus in accordance with this invention have been illustrated in the accompanying drawings and will be described in detail in the disclosure which follows, it is to be understood at the outset that the illustration and disclosure of preferred embodiments of this invention are to be construed broadly and not to be taken as limiting upon the scope of apparatus and methods as contemplated by this invention.

Referring now broadly to the accompanying drawings, the embodiment illustrated in FIGS. 1-9 is particularly intended for use in circumstances where electrical power is readily available at locations where the removal of tenaciously adhered heat degradable textile waste material is to be performed and incorporates an air compressor as a means for delivering a flowing stream of air. The second embodiment of apparatus in accordance with this invention, as illustrated in FIGS. 10-12, is particularly contemplated as useful in circumstances where a central supply of compressed air is readily available at locations where the removal of tenaciously adhered heat degradable textile waste material is to be performed. The embodiment of apparatus in accordance with this invention illustrated in FIGS. 1012 is arranged for connection with such a factory air supply, as will be brought out more fully hereinafter. The disclosure which follows will be directed first to the embodiment of FIGS. 1-9 and will then turn to the embodiment of FIGS. 10-12.

Practice of the method of this invention in a location within a textile plant or the like is facilitated, in the first embodiment of this invention, by mounting the components of the apparatus generally indicated at 20 in or connected with a housing 21 having a handle 22 by which the apparatus may be carried to-a location of use. Within the housing 21 is an electrically driven air generally as indicated compressor-'24, illustrated as being of the type having twodiaphragms oscillated by connection with an electrical motor. The air compressor'24 delivers compressed air into a flexible conduit 25 which extends from within the housing 21. Where a doublediaphragm compressor is used, a characteristic flow rate of compressed air delivered from the compressor 24 would be approximately one cubic foot per minute at a pressure of IS pounds per square inch. Satisfactory operation has been obtained where a single diaphragm compressor was used and approximately 4/ IOths of a cubic foot per minute was delivered. Thus, it is believed that an appropriate range of volumes of air flow would be upward from at least about 4/ IOthscubic foot per minute (CFM). The conduit 25 is sized to pass such flows and pressures substantially unimpedingly, so as to make such flows and pressures available for impingement against the waste material to be removed.

lnaddition to the compressor 24, an electrical cord reel 26 ismountedwithin the housing 21 to permit a power cord 28- to be withdrawn from the housing 21 and electrically connected with appropriate line source of electrical current. By means of the power cord 28,

' electrical power is supplied to the compressor 24 and fully hereinafter.

Air delivered through the conduit 25 passes to a manipulable handle-29 which mounts an electrical resistance heater means generally indicated at 30. The electrical resistance heater means 30 has a metallic sheath 31 having mounted in one end thereof a ceramic core 32 (FIGS. 7 and 8). The ceramic core 32 has a plurality of longitudinally directed openings extending therethrough, with a resistance wire 34 coiled within each of the passageways. Upon electrical energization of the resistance wire 34, the wire is raised to an elevated 'temperature for heating the air'flowing therethrough.

Preferably, the heater means 30 is arranged with an air flow entering section housed within the handle 29 and with a heater section which extends forwardly from 'the handle 29(F'IG. 4). Thus, as operator manipulating the handle 29 so as to' direct the flow of air issuing from the'apparatus toward textile waste material to be removed is protected against contact with that portion of the heatermeans 30 which'may attain an elevated temperature. At the extreme forward end of the heater means 30, a provision is made for the attachment of a separable flow directing nozzle 35, by means of a compression nut 36 secured thereto, a compression union melting otherwise possibly occurring from excessiveheating thereof, this invention contemplates the inclusion of control meansof a particular type and the employment of, resistance elements of a particular type.

Turning 'flrst to the controlarrangements, controlmeans are operatively interconnected with the compressor 24 which delivers airand with the electrical resistance heater 35 for coordinating electrical energiza- '49 for indicating to an tion of the heaterwith delivery of the flowing stream of air. As schematically represented in FIG. 9, such a control arrangement includes an electrical switch means 46 electrically connected between the power cord 28 andthe compressor 24' and heater30. By means of a parallel connection of the conductors leading to the heater means 30 and to the compressor 24, energization of the heater prior to energization of the compressor is not possible. Due to the temperature rise characteristics of the heater as compared to the flow characteristics of the compressor, the heater 30 will not reach an elevated temperature until after such time as the flow of air from the compressor 24 has begun. The electrical circuitry includes ,a fuse 48 for protecting against excessive current requirements and a pilot light operator that the unit is operating. s

It has been found desirable to provide for the possibility of varying the flow of current to the heater 30 and thereby varying the temperature at which air is delivered against textile waste material to be removed. To this end, the control circuitry preferably includes means for varying at least one characteristic of the electrical current flowing to the electrical resistance heater. As schematically illustrated in FIG. 9, a variable resistance 50 is insertedin the conductor 42 leading to the heater 30. In preferred practice of this invention, a thyristor circuit is employed to modulate the phase relation of electrical power delivered to the resistance heater in a manner known to persons familiar with such electronic devices. By way of example and not by way of limitatiomsuch circuits are disclosed in Paragraph 9.4.2 of the SCR Manual, Fourth edition, published by theSemi-conductor Products Department of General Electric Co. i I

In practicing the method of the present invention in removing tenaciously adhered textile waste material by directing a flowing stream of heated air thereagainst, it

moval has been found to proceed most readily where I the air has been heated to a temperature of at least about'l,0O0 F. Accordingly, heating of the air in accordance with this invention preferably follows the latter practice soas to be equally applicable to the removal of thermoplastic and non-thermoplastic textile waste materials.

In choosing an electrical resistance heater for heating the air in accordance with this invention, the wattage of the electrical resistance heater is determined from a formula in which kilowatts of power required equal the weight of air delivered per hour times 0.24 times the number of degrees F. by which the temperature of the air'is raised divided by 3,412. It is preferred that the wattage requirement for the heater be approximated from the formula Kilowatts CFM X Temperature Rise Above Ambient/3,000.

In order to further protect the electrical resistance heater in the apparatus of this invention against premature failure otherwise possibly occurring, the material from which the resistance wire 34 is formed is chosen from among those materials which have a positive temperature coefficient of resistance. That is, those materials which have an increasing resistance as the temperature of the material increases. As applied in the apparatus of this invention, such a resistance heater has a selflimiting characteristic in that the increasing resistance of the wire decreases the power required and flowing therethrough thereby reducing the wattage delivered to the flowing stream of air and limiting the upper temperature attained by the air. Preferably, the material from which the coils 34 of the heater are formed exhibits such a characteristic at temperatures of approximately l,200 F and may be chosen from among alloys of nickel and platinum.

In an operating embodiment constructed in accordance with FIGS. 1-9, and operating within the parameters and described hereinabove, heated air is directed against waste material to be removed by passage from the nozzle means formed by the handle 29, heater 30 and outlet tube 35 with a velocity of at least about 8,000 feet per minute. Such velocities, when within volume and temperature ranges as described hereinabove, do not adversely effect textile apparatus such as bobbins, casters and the like from which tenaciously adhered heat degradable textile waste material is to be removed. However, such velocities, volumes, and temperatures of heated air are effective to entirely remove such residues.

While this invention has been described to this point with reference to the structure illustrated in FIGS. l-9 which is particularly intended for operation by connection to a source of electrical power, this invention also contemplates an alternative embodiment to be used where an external air supply is available. Such a second embodiment is illustrated in FIGS. 10-12, where components comparable to those of the first embodiment described hereinabove are identified by same reference characters with the addition of prime notation. The present disclosure will be directed particularly to the distinctions between the embodiments rather than repeating at length the common characteristics thereof.

The apparatus 20' of FIGS. 10-12 includes an air supply conduit 51 provided with an appropriate coupling 52 for attachment with an external air supply such as is conventionally found in textile mills and the like. Air entering the apparatus 20' through the conduit 51 is filtered in a filter 54 and is delivered to a pressure regulator 55 having a manually operable handle 56 extending through the housing 20. By manipulation of the handle 56, the pressure at which air is delivered to the conduit 25 and thus to the heater means 30' may be selected.

Downstream of the pressure regulator 55 is provided a pressure responsive switch means generally indicated at 58 (FIGS. 11 and 12) which is responsive to the presence of a flowing stream of air passing through conduit 25' to the heater means 30'. In the presence of the flowing stream of air, an associated electrical contact set 59 is closed'to permit energization of the heater 30. Absent the flowing stream of air, contact set 59 is opened to preclude energization of the electrical heater.

1n the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only, and not for purposes of limitation.

That which is claimed is:

l. A method of removing, from apparatus used in textile operations, tenaciously adhered heat degradable textile waste material comprising the steps of:

transporting a manually portable housing to a location at which textile waste material is to be removed,

delivering through the manually portable housing a flowing stream of air at a volume rate of flow of at least about 0.4 cubic feet per minute,

passing the flowing stream of air from the housing through an elongate flexible conduit to a manipulable handle,

passing the flowing stream of air through an electrical resistance heater extending from the manipulable handle and heating the flowing stream of air to a temperature of at least about l,000 F. while it passes there-through,

controllably delivering electrical current to the heater through the housing and through conductors extending between the housing and the handle,

preventing delivery of electrical current through the housing and energization of the heater in the absence of the flowing stream of air and thereby protecting the heater against failure otherwise possibly occurring due to energization thereof while no air is flowing therethrough, and

manipulating the handle to direct the heated air against the waste material to be removed at a velocity of at least about 8,000 feet per minute.

2. A method in accordance with claim 1 wherein the delivering of air comprises electrically energizing an air compressor mounted within the manually portable housing and the prevention of energization of the heater in the absence of air delivery comprises simultaneously switching the flow of electrical current to the air compressor and heater.

3. A method in accordance with claim 1 wherein the delivering of air comprises establishing operative communication with a remote source of air under pressure for delivery thereof through an elongate flexible air supply conduit extending from the manually portable housing and the prevention of heater energization comprises switching the flow of electrical current to the heater in response to the presence and absence of air under pressure.

Dedication 3,84cl,9ll.-James H. Hendeflite [[1, Charlotte, NC. METHOD FOR REMOVING HEAT DEGRADABLE TEXTILE WASTE MATE- RIAL FROM APPARATUS USED IN TEXTILE OPERA- TIONS. Patent dated Oct. 15, 1974. Dedication filed Dec. 6, 1977, by the assignee, Air Knife, Inc. Hereby dedicates to the Public the entire term of said patent.

[Ofiicz'al Gazette March '7, 1.978.] 

1. A METHODD OF REMOVING, FROM APPARATUS USED IN TEXTILE OPERATIONS, TENACIOUSLY ADHERED HEAT DEGRADABLE TEXTILE WASTE MATERIAL COMPRISING THE STEPS OF: TRANSPORTING A MANUALLY PORTABLE HOUSING TO A LOCATION AT WHICH TEXTILE WASTE MATERIAL IS TO BE REMOVED, DELIVERING THROUGH THE MANUALLY PORTABLE HOUSING A FLOWING STREAM OF AIR AT A VOLUME RATE OF FLOW OF AT LEAST ABOUT 0.4 CUBIC FEET PER MINUTE, PASSING THE FLOWING STREAM OF AIR FROM THE HOUSING THROUGH AN ELONGATE FLEXIBLE CONDUIT TO A MANIPULABLE HANDLE PASSING THE FLOWING STREAM OF AIR THROUGH AN ELECTRICAL RESISTANCE HEATER EXTENDING FROM THE MANIPULABLE HANDLE AND HEATING THE FLOWING STREAM OF AIR TO A TEMPERATURE OF AT LEAST ABOUT 1,000*F. WHILE IT PASSES THERE-THROUGH, CONTROLLABLY DELIVERING ELECTRICAL CURRENT TO THE HEATER THROUGH THE HOUSING AND THROUGH CONDUCTORS EXTENDING BETWEEN THE HOUSING AND THE HANDLE, PREVENTING DELIVERY OF ELECTRICAL CURRENT THROUGH THE HOUSING AND ENERGIZATION OF THE HEATER IN THE ABSENCE OF THE FLOWING STREAM OF AIR AND THEREBY PROTECTING THE HEATER AGAINST FAILURRE OTHERWISE POSSIBLE OCCURRING DUE TO ENERGIZATION THEREOF WHILE NO AIR IS FLOWING THERETHROUGH, AND MANIPULATING THE HANDLE TO DIRECT THE HEATED AIR AGAINST THE WASTE MATERIAL TO BE REMOVED AT A VELOCITY OF AT LEAST ABOUT 8,000 FEET PER MINUTE.
 2. A method in accordance with claim 1 wherein the delivering of air comprises electrically energizing an air compressor mounted within the manually portable housing and the prevention of energization of the heater in the absence of air delivery comprises simultaneously switching the flow of electrical current to the air compressor and heater.
 3. A method in accordance with claim 1 wherein the delivering of air comprises establishing operative communication with a remote source of air under pressure for delivery thereof through an elongate flexible air supply conduit extending from the manually portable housing and the prevention of heater energization comprises switching the flow of electrical current to the heater in response to the presence and absence of air under pressure. 